Demo: Loading Macros via include-in-header

This page demonstrates the include-in-header strategy for loading macros. The YAML front matter of this file includes:

format:
  html:
    include-in-header:
      - macros-header.html   # MathJax macro config script
  pdf:
    include-in-header:
      - macros.qmd           # raw LaTeX goes directly into preamble
  revealjs:
    output-file: demo-include-in-header-slides.html
    scrollable: true
    center: false
    include-in-header:
      - macros-header.html   # loader that reads macros.qmd
  docx: default

Note (HTML/RevealJS): macros-header.html is a small loader script (not a second macro-definition file). It reads macros.qmd, converts macro definitions to a MathJax config object, and sets MathJax.tex.macros before typesetting. For RevealJS, it also forces the built-in Reveal math plugin to use MathJax 3. This requires macros.qmd to be published as a static resource in the site output. View the RevealJS slides output.

Note (PDF): For PDF, macros.qmd can be included directly since its raw LaTeX goes into the document preamble.

Note: This demo uses macros-header.html / macros.qmd because both files are at the root of this repository. When using this repository as a Git submodule (cloned into a macros/ subdirectory), replace with macros/macros-header.html and macros/macros.qmd.

The same configuration can be placed in a shared _quarto.yml to apply project-wide:

format:
  html:
    include-in-header:
      - macros/macros-header.html
  pdf:
    include-in-header:
      - macros/macros.qmd
  revealjs:
    include-in-header:
      - macros/macros-header.html

This inserts the macro definitions for each output format:

• PDF: macros.qmd goes into the LaTeX preamble via include-in-header — all macros work, including \providecommand.
• HTML: macros-header.html is inserted via include-in-header and loads macros from macros.qmd into MathJax.tex.macros.
• RevealJS: macros-header.html does the same loader step and switches the Reveal math plugin to MathJax 3, so slide math uses the same macros.qmd source.
• docx: Word documents do not use a LaTeX preamble or MathJax header, so include-in-header has no effect on math rendering for docx. The docx: default entry above produces docx output without macro support.

Example math

The table below uses macros defined with \def in macros.qmd, which work in all output formats that support MathJax or LaTeX:

Description	Code	Output
Greek: alpha	\a	\(\alpha\)
Greek: beta	\b	\(\beta\)
Greek: gamma	\g	\(\gamma\)
Greek: lambda	\l	\(\lambda\)
Greek: sigma	\s	\(\sigma\)
Log-likelihood	\llik	\(\ell\)
Independent	X \ind Y	\(X \perp\!\!\!\perp Y\)
IID distributed	X_i \siid \Normal(\m, \ss)	\(X_i \ \sim_{\operatorname{iid}}\ \operatorname{N}(\mu, \sigma^2)\)
Vector: mu	\vm	\(\tilde{\mu}\)
Hat beta	\hb	\(\hat \beta\)

Color macros

macros.qmd defines a one-argument macro for each of the 19 LaTeX base colors (\red, \blue, \green, \orange, …), using the \color switch form ({\color{red}{#1}}), which is supported by MathJax (HTML/RevealJS) and lualatex (PDF):

Description	Code	Output
Red	\red{x}	\({\color{red}{x}}\)
Blue	\blue{y}	\({\color{blue}{y}}\)
Green	\green{z}	\({\color{green}{z}}\)
Orange	\orange{\mu}	\({\color{orange}{\mu}}\)
Combined	\red{x} + \blue{y} = \green{z}	\({\color{red}{x}} + {\color{blue}{y}} = {\color{green}{z}}\)
Nested macros	X_i \sim_{\red{\ind}} \blue{\Normal}(\orange{\mu_i}, \green{\ss})	\(X_i \sim_{{\color{red}{\perp\!\!\!\perp}}} {\color{blue}{\operatorname{N}}}({\color{orange}{\mu_i}}, {\color{green}{\sigma^2}})\)

Note (docx): as described above, the include-in-header strategy does not load macros for docx output, so the color macros (like all other macros) are unavailable there. For docx, use the include shortcode strategy instead.